Two brothers, Ben and Clint, join a cattle drive from Texas to Montana. While heading for Texas they save Nella from the Indians, and she decides to ride with them. Ben and Nella start to get romantic, but Ben isn't ambitious enough for her, and she soon meets up with the boss of the cattle drive. Will she make the right choice, and, more impotantly, will the cattle make it to Montana !

In 1866, brothers Ben and Clint Allison, disillusioned after fighting with Quantrell's Raiders during the Civil War, turn outlaw and spend several months committing robberies. The brothers travel to Mineral City in the Montana territory, where they spot entrepreneur Nathan Stark donning a money belt in a saloon. Ben and Clint rob Stark, then, fearing that he will alert the vigilantes, force him to accompany them to a distant shack. The Allisons intend to release Stark the next day, and are surprised when he offers them a partnership in his scheme to drive a huge herd of cattle from Texas, where they can be bought cheaply, over the Bozeman Trail to Montana, to be sold at a huge profit. Although no one has ever driven a herd such a long distance, Ben sees the plan's potential and, with Clint, agrees to return to their native Texas with Stark. The men begin the long journey to Texas, and during a blizzard, are forced to stop at Timpas Grove. There, they find a stranded group of settlers who were headed for California. Ben is immediately attracted to fiesty Nella Turner, as she is to him. In the morning, when the weather has cleared, the trio of men ride on, but soon spot an Ogala Sioux war signal. Ben orders Clint to continue on with Stark while he rides back to warn the settlers. When he reaches the grove, Ben finds that all of the settlers except Nella have been killed by the Indians. Ben rescues Nella, although another storm forces them to take shelter in an abandoned cabin. The couple fall in love, but as they discuss their future, Ben states that all he wants is a quiet life on a Texas ranch. Nella bitterly recounts how the hard life of a rancher killed her mother and asserts that she "dreams big." Ben, who "dreams small," cannot reconcile himself to Nella's desire for a grand future in California, and the pair angrily ends their courtship. They then travel to an Army outpost, where they learn that Clint and Stark have gone on to San Antonio. Nella is forced to accompany Ben to San Antonio, as there are no stagecoaches from the post to California, and there she is aggressively courted by Stark. Although Nella is nonplussed by the educated Stark's attempts to turn her into a lady, she recognizes that he can make her big dreams come true. Stark buys a huge herd of cattle, and Ben organizes the wranglers, who are led by Ben's devoted friend, Luis Estrella. As they begin the cattle drive, Ben is dismayed to learn that Nella will be accompanying Stark to Montana. Later, the group comes across some settlers, who tell them that they were attacked by Jayhawkers, a renegade group of Kansans who extort huge tolls from anyone crossing the state line. Stark favors paying the toll, but Ben refuses, and when the Jayhawkers confront them, Ben's men prevail in a gunfight. As the journey continues, the hot-headed, often drunk Clint clashes with Stark, whom he despises. When the herd reaches Ft. Bozeman, the beginning of the Bozeman Trail, Col. Norris informs the Allisons that the trail is closed due to the increased violence of the Sioux. Ben again refuses to be put off course and allows only a few days rest for the herd. One afternoon, as Clint taunts Nella while she bathes in a river, Stark intervenes and shoots Clint's revolver out of his hand during a fair draw. Clint is angered by the event, and drunk, attempts to shoot Stark later. Ben stands between Clint and Stark, and eventually Clint relents, although he is so embarrassed by his actions that he runs away. Ben searches for Clint for two days to no avail and begins the drive again. Ben finds Clint soon after, and an abashed Clint promises to reform. Clint asks to ride point so that he can avoid Stark, and Ben agrees, although he regrets his decision after Clint is killed by the Sioux. After Clint is buried, the grief-stricken Ben scouts ahead and discovers that the Indians have the group boxed in, forcing them to travel through a canyon to reach Montana. The canyon is perfectly situated for an ambush, and in order to prevent the Sioux from slaughtering them, Ben orders Luis to stampede the cattle through the canyon. Ben and Nella forgive each other for their earlier taunts as they prepare for the dangeous ride, and soon the stampede begins. Ben's strategy works, and the group survives without losing many cattle. Stark and Nella ride ahead to Mineral City to sell the cattle, while Ben and the men rest the herd. When Ben arrives at Stark's saloon for his share of the profits, however, Stark tries to have him arrested by the vigilantes in retribution for Ben's earlier attempt to rob him. Suspecting that Stark would double-cross him, Ben had ordered his men to take over the saloon, and Stark is forced to release Ben. Ben takes only a small portion of the profits, and as Ben leaves, Stark admits that he is the only man he has ever respected. When Ben, Luis and the others return to camp, Luis realizes that Ben's gloomy demeanor is caused by his lingering love for Nella. Ben quickly cheers up, however, when he finds Nella, who has realized that only he can make her truly happy. Nella sings a song about settling down with Ben in his hometown, then playfully asks Ben to take off her boots.